Had the same problem with the previous 85mm f1.8. Sharp?! Not even close!!! I think they have an unacceptable percent of quality control issues.

My 85mm f/1.8G is very very good ... however, my D300 can't quite focus it correctly - focussing at f/1.8-f/2.5 reveals what looks like a slight tendency to front focus in my D300 (absolutely fine when using Live View or when on my D200, though, and my 50mm f/1.4 seems to be doing the same thing wide open - I've never shot them really wide, it and all my other lenses are fine at f/2.8, and a -5 focus adjustment covers it). Don't know if that might be the culprit..?

He bought the 1.8G, not the 1.4G. So we're back at halves, the 1.8G is half the cost of the Sigma 1.4 .

Whoops, my bad...Anyway I Just checked and perhaps not supprisingly the Sigma is sharper at every aperture than the 1.8 G.

That is not the whole story.

While the Sigma is marginally sharper in the centre, the Nikon is much sharpe everywhere else. The Sigma may be better suited for portraiture, but the Nikon appears to be the better all round lense at a much lower price.

And the conclusion of the FotoZone review concurs

Although I do understand from your forum ID that it is difficult for you to form an impartial view about this.

Whoa...That's a low blow! My Dpreview name refers to my Sigma DSLR's, not my lenses. I am actually very impartial as I don't use Sigma lenses on my Sigma DSLR's (well I do have one, a 14mm f3.5) but otherwise I only use Canon lenses, Nikon lenses, Carl Zeiss lenses and many more.

The digital picture shot you provide is improperly focused. Please see the 85/1.8G example I provided earlier in this thread, of the same rez chart, with a D800E, wide open...

-m

I also took several shots at night with this lens and the results are just the same: non-Black central area. I believe I focused properly - so this lens /for me/ went into no-buy category.. just hate this effect.

Well i finally got around to buying one after I sent back the Samyang.

Whats the deal wiith the CA ??? It also doesnt seem that sharp. I microfocus adjusted it today. Really its isnt that good.

Is my copy a dud? look at the photo and click look at it at 100%. The phot is a 60% crop, the focus point is the on the edge of the wood toward the right. Look at all the green CA on the left.................... and its red to the right (which was cropped off)

Is this lens a BAD copy ????????????

The Lens Align Ruler looks horrible, indistinct focus point at F1.8 and CA in both directions each side of the fuzzy focus point. I am really bummed by this.

Can someone post some 100% crops so I can see what their copy is like?

What you have now learned is that you should always do your own research before buying lenses and never simply buy into the hype.

Yes, research will tell you (see links below) that the Nikkor are about as good as it gets for portrait lenses.

I know its a bit late but I can tell you now that the Sigma 85mm f1.4 EX has 30% less barrel distortion that the G, 20% less vignetting wide open than the G, its sharper wide open than the G, its actually sharper at f2 that the G is at f2.8! And what's more, it costs about half the price!

The Sigma has poor corners relative to the Nikkors, so I'm not sure what all this talk about sharpness is.

Yes, the Sigma isn't as good at the corners or edges of frame but the photozone results clearly show that the Sigma is considerably sharper in the centre of frame than the f1.8 G, and at every comparable aperture. So as its a portrait lens, and you only need the centre for pro portrait work, the Sigma shouldn't be ruled out as a attractive lens option, unless of course your on a tight budget. BTW, I couldn't afford the Sigma myself but then I don't need one as I have a Canon FD 85mm f1.2 L instead, which is about as good as it gets 85mm lens wise.

I found these figures quickly and easily by simply comparing their test results on Photozone, where they were both tested on a FF D3X.

So should you sell the Nikon and get the Sigma instead so you can not only get a better lens but also save yourself about £600 in the process?...That's entirely up to you.

I'm surprised you even brought up Photozone as both the f1.4G and f1.8G Nikkors received "Highly Recommended" awards and the Sigma 85 1.4 did not.

What's that got to do with anything? How do you know the Nikon rep didn't simply grease the palm of Photozones tester/s to help them get an award? Or that perhaps the Photozone tester/s simply has a heavy Nikon bias?

The 1.8 G only got its award for its far better bang per buck than the Sigma...The Sigma is almost twice the price so of course its not going to get an award.

However, as I mentioned before, the Sigma has 30% less barrel distortion that the f1.4 G, 20% less vignetting wide open than the f1.4 G, its sharper wide open than the f1.4 G and its actually sharper at f2 than the f1.4 G is at f2.8! Now factor in the fact that the Sigma is about half the price of the f1.4 G and therefore it offers far more bang per buck, it should be the Sigma that has the highly recommended award, NOT the f1.4 G!

Lets face it, Nikon has a virtually unlimited corporate entertainment budget, so its extremely likely that the tester/s were simply promised free Nikon gear in return for a little "highly recommended" award here and there. Sigma has no corporate entertainment budget whatsoever so of course they can't ever hope to sway an award like Nikon can.

The digital picture shot you provide is improperly focused. Please see the 85/1.8G example I provided earlier in this thread, of the same rez chart, with a D800E, wide open...

-m

I also took several shots at night with this lens and the results are just the same: non-Black central area. I believe I focused properly - so this lens /for me/ went into no-buy category.. just hate this effect.

OK, I tested my 85mm 1.8G again with a focus chart (printed in black).

It is sharp at f/1.8. Obviously not as sharp as when reducing the aperture, but for f/1.8 it is sharp (I'd say very sharp for an f/1.8 lens wide open).

Now here's why I only commented on sharpness... I'm colourblind. So I can't reliably judge any of the colour issues you mentioned.

I'm 99% sure my lens doesn't have the strong purple-instead-of-black issue (how is it called?) in the center, such as shown by websites such as TDP. I say 99% because, being colourblind, I just can't say it is 100% sure. But I can absolutely see it on TDP and it is obiously not like that.

My lens does seem to have the colour issues in the out of focus areas, with different colours in the front blur and back blur. I'm not sure what the colours are, but the back seems blue-purple type and the front looks red-green type of colour. It looks more or less similar to what Photozone shows in their Bokeh Fringing example (different targets, condition, etc. so can't expect it to be identical I guess). So I'd say this is normal for this lens (and probably many others, at least the 85mm 1.4G seems similar in the Photozone review).

I guess I've never even noticed this because, first, I'm colourblind and second, because it gets "swallowed" in my photos, as opposed to a test chart which shows it best.

But I have to emphasize that the severe non-black colour doesn't happen with my lens!

Edit: I just asked a non-colourblind person and I was right. The center looks absolutely black and not at all the blue/purple that some examples show. The bokeh fringing exists and it is mostly purple at the front and mostly green at the back.

I think the main point is that Robert loves his lens No harm in that. As to all the comparatives and superlatives in this thread, those should probably be left to actual side-by-side analysis, not subjective opinions.